1. Field of the Invention
The present invention relates to a drilling machine that drills boltholes for fastening connecting plates on abutting railroad rails during the laying and repair of a railroad track.
2. Description of Related Art
Connecting plates are positioned for reinforcement on railroad rails and fastened to them with bolts during the laying of railroad track and the replacement of worn track. During this process, a specified number of boltholes are drilled in the middle part of the rail. However, since the drilling height and pitch of the bolt insertion holes on the connecting plates are predetermined for each type of rail, holes must be drilled in the rails to match the bolt insertion holes on the connecting plates.
The conventional method of drilling boltholes in railroad rails was to first determine the position of the holes to be drilled in each rail and then make punch marks, after which a drill was directed to the marks and the holes were drilled. Marking and punching each rail was tedious and handling the heavy drilling machine was a cumbersome task. There was thus a demand for a drilling machine capable of the simple and rapid operation needed when changing railroad rails in emergencies.
The present invention, devised out of the need to address such drawbacks present in the prior art, has, as its object, to provide a drilling machine for railroad rails that requires none of the marking and punching of conventional rail drilling procedures, and that permits simple and rapid adjustment of the drilling machine on, and drilling of, all types of rail.